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Biomedical subjects

M Rovatti

Publications and source records attributed to M Rovatti.

11 recordsLinked to original sources
PubMed2004

An environmentally sustainable decision model for urban solid waste management.

The aim of this work is to present the structure and the application of a decision support system (DSS) designed to help decision makers of a municipality in the development of incineration, disposal, treatment and recycling integrated programs. Specifically, within a MSW management system, several treatment plants and facilities can generally be found: separators, plants for production of refuse derived fuel (RDF), incinerators with energy recovery, plants for treatment of organic material, and sanitary landfills. The main goal of the DSS is to plan the MSW management, defining the refuse flows that have to be sent to recycling or to different treatment or disposal plants, and suggesting the optimal number, the kinds, and the localization of the plants that have to be active. The DSS is based on a decision model that requires the solution of a constrained non-linear optimization problem, where some decision variables are binary and other ones are continuous. The objective function takes into account all possible economic costs, whereas constraints arise from technical, normative, and environmental issues. Specifically, pollution and impacts, induced by the overall solid waste management system, are considered through the formalization of constraints on incineration emissions and on negative effects produced by disposal or other particular treatments.

Cities↗
PubMed1999

Terminal settling velocity and bed-expansion characteristics of biofilm-coated particles.

Fluid dynamic behavior of biofilm-coated particles in ambient water has been investigated. New experimental results are presented and compared with published data. From experimental measurements of the single particle terminal settling velocity the corresponding drag coefficient was found to be larger (by a factor of 1.6) than that for a smooth, rigid sphere at the same Reynolds number. A new simple correlation describing this finding is suggested. For multiparticle systems the Richardson-Zaki equation, derived empirically for rigid particles, provided a satisfactory description of biological beds. Of the two numerical parameters characterizing the expansion law, i. e. the slope n and the extrapolation to voidage equal one ui, the first was found to be similar to that suggested by Richardson and Zaki (1954), whereas ui gave results smaller than the single-particle terminal settling velocity, in contrast with the mentioned work but in agreement with more recently published behavior.

Biofilms↗
PubMed1995

[Efferent loop obstruction by a phytobezoar after gastrectomy].

The authors present one case of intestinal obstruction due to phytobezoar of the efferent loop, in a previously undergone gastric surgery patient. They report, in the light of bezoar's peculiar location, that is usually it found in the stomach or small bowel.

Aged↗
PubMed1995

[Multiple primary malignant neoplasms].

Multiple primary malignant neoplasms (MPMN) are tumors that arise independently in the same organ or tissues and different organs; they may present simultaneously (synchronous) or at least 6 months later (metachronous). The authors report the case observed: 20 multiple neoplasms in 5 years (5.8% of the tumors). In the light of the international literature they analyze some aspects of the problem, particularly with regard to the classification, etiopathogenesis, neoplasm associations and possible genetic character for some of there.

Adult↗
PubMed1983

An experimental study on fluorocarbons as blood substitutes.

A fluorocarbon emulsion (Fluosol DA 20%) was experimented as a blood substitute. Fourty-five rats weighing 320 +/- 30 g. underwent different degrees of hemodilution, by isovolemic exanguino-transfusions. A first group (15 rats) had maximal exchange transfusion (Ht = 0,5%) with Fluosol DA 20% and was followed for 12 hours. A second group (15 rats) (control group) underwent the same procedure, but hydrolyzed gelatin 3% (Emagel) was used instead of Fluosol DA 20%. A third group (15 rats) had partial exchange-transfusion (Ht = 23 +/- 2%) with Fluosol DA 20%, and was followed for 2 months. Cerebral and cardiovascular activity, respiratory exchanges and acid-base balance as well as other basic biological parameters were evaluated in the first and second group. The initial signs of altered cerebral activity were observed with a Ht = 2%, while death occurred at Ht = 0,5% due to respiratory arrest. In the third group, a retention of fluorocarbon particles was demonstrated by gas chromatography in all the organs examined. In this group, lung and spleen lesions were also observed by light microscopy and transmission electron microscopy.

Acid-Base Equilibrium↗
PubMed1981

[Contamination of the operating room by anesthetic gases and vapors. II. Gas chromatographic analysis of nitrous oxide].

The contamination by nitrous oxide of an operating room atmosphere was studied in a number of experiments, in the absence of personnel and using a gaschromatographic method. The evacuating device of the anesthesia machine proved to be ineffective to overcome the hazard of leaks in the breathing system, whereas the air conditioning flow rates (12 outside air changes per hour) minimized waste anesthetic gas concentrations.

Air Pollution↗
PubMed1979

[Contamination of the operating room with anesthetic gases and vapors. Analytical methods].

An approach for the measurement of the contamination of the operating room air is presented. The measurements were performed in three operating rooms used for general surgery, partly in model experiments and partly while anesthesia was in progress. During anesthesia, the measurements were taken when oxygen 3 l/min containing ethrane 1.0--1.5% was passed into a semi-closed circle and the exhaled gas vented directly to the environmental air with no scavenging system in use. The daily exposure of operating room personnel was determined by adsorption of ethrane on glass tubes containing activated charcoal. The ethrane was subsequently desorbed in toluol and quantified by gas chromatography. The concentration of contaminant was found to be significantly greater in the anesthesiologist's position than in the areas of surgeon and circulating nurse. Some pitfalls in sampling, standardization, and analysis are indicated. Attention is drawn to the numerous factors influencing the extent of contamination.

Air Pollution↗
PubMedDate not supplied

[Biliary ileus].

The authors report a retrospective review of four cases of gallstone ileus seen at Semeiotica Chirurgica, at Patologia Chirurgica II and Clinica Chirurgica II of Policlinico San Matteo I.R.C.C.S. of Pavia between 1974 and 1989. Three patients were women and one male, with average age 69.4 years. All obstructions occurred in the distal ileum. Proceeding from available data in the literature and from their personal experience the Authors emphasize that gallstone ileus is a rare cause of mechanical obstruction of intestine (4% of the obstructions of the small bowel). This disease usually occurs in elderly women, with concomitant illness. Approximately 50 per cent of the patients have an history of gallbladder disease. The authors discuss the controversy on performing an enterolithotomy alone versus one stage procedure consisting of removal of the impacted stone, fistula repair and cholecystectomy. The prognosis is severe. High mortality and many postoperative complications are caused by the advanced age of the patients, concomitant illness and usually delayed diagnosis.

Aged↗